I picked up a 1991 Firebird 3.1L that starts & runs fine when cold, I can stop and restart as much as I want, until it reaches full operating temperature. Once warm it will not restart. It starts but dies immediately until it is completely cooled down.
I had a problem when we first started it, that it would die whenever I gave it gas. I disconnected the vaccuum line to the MAP Sensor and it would accelerate to red line without issue. After the car ran for a little bit, I reconnected the vaccuum line and it still rev'd all the way to red line and was running fine. It would restart, while cold, just fine - with or without the MAP sensor's vaccuum line connected, I was still able to take it all the way through the Tach. Once it is warm I still have the no-start condition listed above, with or without the MAP Sensor vaccuum connected.
When the MAP sensor is connected it is not showing a 'Check Engine Light' with the sensor disconnected the light is coming on. I have not hooked it up to a code reader as of yet, the previous owner said that it was not throwing any flags and he could not get it to run any more than what is listed above.
I'm thinking it might be the fuel pressure regulator but want another opinion on these, or any info on where I can find a cheap regulator.
There is spark when its warm. I have not checked the Fuel Pressure If I touch the accelerator pedal at all it will not fire then die, it'll just turn...
The fuel pump and computer have been replaced already.
Any suggestions?
Thank you.